Re: [Patch v3 13/13] x86/speculation: Create PRCTL interface to restrict indirect branch speculation

[Randy Dunlap]

On 10/17/18 10:59 AM, Tim Chen wrote:
> 
> Signed-off-by: Tim Chen <tim.c.chen@xxxxxxxxxxxxxxx>
> ---
>  Documentation/admin-guide/kernel-parameters.txt |  5 +-
>  Documentation/userspace-api/spec_ctrl.rst       | 10 +++
>  arch/x86/kernel/cpu/bugs.c                      | 85 ++++++++++++++++++++++++-
>  include/linux/sched.h                           | 11 ++++
>  include/uapi/linux/prctl.h                      |  1 +
>  tools/include/uapi/linux/prctl.h                |  1 +
>  6 files changed, 111 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 2feb6b2..9af11be 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -4196,7 +4196,10 @@
>  			lite   - turn on mitigation for non-dumpable
>  				 processes (i.e. protect daemons and other
>  				 privileged processes that tend to be
> -				 non-dumpable).
> +				 non-dumpable), and processes that has indirect

				                                   have

> +				 branch speculation restricted via prctl's
> +				 PR_SET_SPECULATION_CTRL option
> +
>  			strict - protect against attacks for all user processes
>  			auto   - let kernel decide lite or strict mode
>  



-- 
~Randy